The United States Geological Survey said that a 7.4 magnitude earth quake shook the south Atlantic ocean early Friday with an epicenter 195 miles from islands hosting British Antarctic research stations.

At least five aftershocks were reported by the USGS.

There was no instant tsunami warning following the earth-quake.

The quake struck at a depth of 10 kilometers at local time 5.32am.

It was centered east-southeast of the remote British-administered South Georgia and South Sandwich Islands, which are about 620 miles east of the Falkland Islands.

The islands are residence to two British Antarctic Survey stations that jointly hold up to 32 researchers.